Outcomes and Predictors of Different Flow-Gradient Patterns of Aortic Stenosis After Transcatheter Aortic Valve Replacement

Abstract

This study sought to explore the clinical factors associated with classical low-flow low-gradient (C-LFLG) and normal-flow low-gradient (NFLG) aortic stenosis (AS) compared with high-gradient (HG) AS. We also compared clinical and echocardiographic outcomes after transcatheter aortic valve replacement (TAVR) across flow-gradient patterns. Patients with C-LFLG AS have a higher mortality rate after TAVR than those with HG AS. However, what leads to C-LFLG AS and the predictors of mortality in this population remain unclear. In this retrospective, single-center study involving 1,415 patients with severe AS, patients were classified as having (1) HG AS (aortic valve mean gradient [MG] >40 mm Hg), (2) C-LFLG AS (MG <40 mm Hg, stroke volume index <35 ml/m², left ventricular ejection fraction <50%), and (3) NFLG AS (MG <40 mm Hg, stroke volume index ≥35 ml/m², left ventricular ejection fraction ≥50%). Logistic regression was used for predictors of C-LFLG AS. Cox regression was used for predictors of mortality in the C-LFLG AS population. Male gender, multiple co-morbidities, and moderate to severe mitral and tricuspid regurgitation correlated with the C-LFLG AS group. Patients with C-LFLG AS had a higher mortality risk compared with patients with HG AS at 2 years after TAVR. Patients with NFLG AS had similar mortality at 1 year, but higher mortality at 2 years after TAVR compared with patients with HG AS. End-stage renal disease, atrial fibrillation, and other co-morbidities were predictors of 2-year mortality in patients with C-LFLG AS. In conclusion, the mortality rate after TAVR was higher among patients with C-LFLG AS than those with HG AS. Male gender and multiple co-morbidities were predictors of C-LFLG AS. Multiple co-morbidities were predictors of mortality among those patients.